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Homebuilt CNC in Tokyo

Bakafish

Aluminum
Joined
Feb 21, 2022
Was thinking more about (aside from renting some space and buying a used CNC) how I would approach the problem the OP has: small space, limited 1-phase electrical, limited budget. A bit wild but I wonder whether aquiring an old small horizontal mill like a Burke No 4 and converting to CNC might be interesting. The work envelope would be smaller than OPs current plans, but the machine could cut anything....those little guys were very robust within the work envelope they presented. There is a challenge to having sufficient power to raise/lower the z/knee that would need solving. One could put a very nice head on it such as a Bridgeport M or Rusnok. Also, one gets a universal mill, both vertical and horizontal spindles.

Part of the WAF is that I built it myself, and that it looks more like a robot than an old industrial machine. I love the looks of old iron, but I can understand my wife's feelings on that. So converting an existing machine (if a good set of bones could be found) is certainly a more straightforward approach, but it just would put a lot more pressure on me to 'get that thing out of the house' if you understand. Due to the big castings it would also be much harder to move, support and dispose of. My machine's largest parts (other than the base plate) are all 30kg or less, and are small enough in size that they can be disposed of without special handling. I plan for success, but I plan for failure too.
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Part of the WAF is that I built it myself, and that it looks more like a robot than an old industrial machine. I love the looks of old iron, but I can understand my wife's feelings on that. So converting an existing machine (if a good set of bones could be found) is certainly a more straightforward approach, but it just would put a lot more pressure on me to 'get that thing out of the house' if you understand. Due to the big castings it would also be much harder to move, support and dispose of. My machine's largest parts (other than the base plate) are all 30kg or less, and are small enough in size that they can be disposed of without special handling. I plan for success, but I plan for failure too.

Requirements for the machine:
- small
- not too noisy
- 1-phase, low amperage power
- not too expensive
- must appear modern/robot like, not classic machine/industrial look from WWII
- components must be lightweight so can be easily moved around and disposed of
- must be built from scratch, not allowed to utilize previously created cast iron bodies

Good luck!!!
 

Bakafish

Aluminum
Joined
Feb 21, 2022
Requirements for the machine:
- small
- not too noisy
- 1-phase, low amperage power
- not too expensive
- must appear modern/robot like, not classic machine/industrial look from WWII
- components must be lightweight so can be easily moved around and disposed of
- must be built from scratch, not allowed to utilize previously created cast iron bodies

Good luck!!!

That's a pretty good summary :) although I planned on mitigating the noise after the fact, it isn't one of the initial primary criteria, I suspect it will be really loud to begin with. I'd also add to that list that I am doing everything I can to use domestic parts, and ideally recycled/salvaged stuff. Save the planet and everything.

To be honest if I had come across something that was well built enough to serve the purpose and meet my needs I would have (will) buy it. Being built by me is not as important as doing what I need it to do, I was just saying that my wife will have a softer place in her heart knowing I put it together myself. I hope that's understandable. And as far as the expense, I wanted to keep it under $10k, which is cheap compared to a Brother Speedio, but reasonable compared to hobbyist machines. I've not spent anything like that much so far, but I think the impression that I'm cheaping out or making crazy compromises over costs isn't really fair, I just feel like I've been fortunate to find what I need cheaply.

I get the sense (although I've misread you before) that you may not think these are reasonable pre-requisites, or achievable goals, and I can understand that. But I've said before that defining the constraints helps focus the details, and even though I may not have done a good job of communicating them, they have been clear enough in my own head to guide my design.

This is something I've been thinking about for years, and actually committed to working on seriously for the last year, so I've made a lot of decisions that may look arbitrary from the outside or sound like I'm just making up excuses when I try to explain them after the fact. You will have to trust me when I say, I believe I've thought of the same solutions you guys are coming up with along the way. I know I sound defensive, a lot of it is getting annoyed that I feel condescended to that I haven't thought of these (obvious?) things, or don't understand my own situation better than someone who just jumped into a post for the first time. I'm not trying to make this harder than it needs to be out of whimsy. The fact that I dismissed these suggestions doesn't mean they are wrong, just that I considered them and they didn't work for me. I'm not saying I've thought of everything, or know everything, or even that I know this will work, one of you may blow my mind and change my direction entirely. I just hope those of you who are actually trying to be supportive can understand my attitude, and why I'm doing it this way.
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
The requirements I would always start with when designing a machine are:
- what materials do you want to cut?
- what tolerance do you require?
- what repeatability do you require?
- what surface finish quality do you require for each target material?
- how fast do you want the machine to be in terms of cut through speed for any given target material?
- how deep do you want your cuts to be for a given pass and target material?
- how will you handle tool changes?
- how will you handle coolant? do you plan on using coolant?
- how will you handle swarf?
- how will you handle maintenance of the machine, e.g. lubrication?
- what is max noise level you are willing to tolerate noting that this will change with different materials?
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
I get the sense (although I've misread you before) that you may not think these are reasonable pre-requisites, or achievable goals, and I can understand that. But I've said before that defining the constraints helps focus the details, and even though I may not have done a good job of communicating them, they have been clear enough in my own head to guide my design.

I have no skin in your project. As an entrepreneur myself, I STRONGLY encourage you to continue working on your dream. Don't let anyone stop you or discourage you (especially not me). That being said, I continue to be very confused about exactly what your target goal is with respect to cutting ability of the machine. If you want to cut wood, you will succeed. Ditto for plastic. If you want to cut metal (at least more than aluminum), you are going to struggle to get quality results with your current design, IMHO....I could be wrong, but that is my view currently.

Some have said, just go ahead and build the machine and see how it works....there is merit in this if you consider it a proto-type for learning how to get into this game. I would suggest working through your requirements as mentioned above, and do some analysis of your design first, as if I were doing this project I'd want to understand the engineering design underpinnings of each decision being made, but that is just me....I tend to be very analytical.
 

Bakafish

Aluminum
Joined
Feb 21, 2022
I have no skin in your project. As an entrepreneur myself, I STRONGLY encourage you to continue working on your dream. Don't let anyone stop you or discourage you (especially not me). That being said, I continue to be very confused about exactly what your target goal is with respect to cutting ability of the machine. If you want to cut wood, you will succeed. Ditto for plastic. If you want to cut metal (at least more than aluminum), you are going to struggle to get quality results with your current design, IMHO....I could be wrong, but that is my view currently.

Ha ha, don't worry about me getting discouraged. People's doubts that I can do something they think overly ambitious has been motivating me my entire life. :)

And I totally understand your perspective about clearly defining the capabilities of the machine's work product. But I'll be honest that my answers to most of those questions is, "as good as possible" other than the speed (which is not important to me at all at this time) and I don't know that defining them could really do much to change the design. Do I want mirror polish, micon level output? Of course! Can I live with machine marks and 0.1mm accuracy? Yeah, honestly, it will still work for what I picture myself doing short term. I'm making it as strong as I can with the materials that I can process. I'm hoping the machine itself can bootstrap itself by manufacturing its own improvements as well. Until I see it fail at those fundamental tasks, it doesn't make sense to me to make the drastic design changes and investments required to upgrade the structure or motors.

And as I said before, I'm really hoping to be able to cut steel, but I'm well aware of how difficult and unlikely that is. I would be disappointed, but not consider it a failure if all I could cut was Aluminum. Right now I either need to hand machine metal parts (on my very undersized equipment) or use 3D printed parts, which I'm really happy with but obviously have strength and heat resistance issues making them unsuitable for many of my current needs. So I'm hoping this will get me to that next level of manufacturing, even if it is slow, noisy and makes a giant mess.

Some have said, just go ahead and build the machine and see how it works....there is merit in this if you consider it a proto-type for learning how to get into this game. I would suggest working through your requirements as mentioned above, and do some analysis of your design first, as if I were doing this project I'd want to understand the engineering design underpinnings of each decision being made, but that is just me....I tend to be very analytical.

I'm a whole stage of business behind where it seems that you think I am, which is where I think the dissonance is coming from. This project is absolutely a learning project, I don't even consider it a prototype as it implies others will be built after it and you've already got me dreaming of the Brother Speedio you have. It is in service of making my own proof of concept prototypes and gaining more first hand experience with the process. I'm fortunate to have a wife that earns far more than I do, and I can quit my engineering position any time I want, but I'm a bit old fashioned and want to show her some actual products and plans before retiring and investing the many hundreds of thousands of dollars to get a setup like yours.

As I'm employed full time for as long as I want, I can afford to take lots of time to make a part, and have bad finish and tolerances, since the customer is me and I only really care right now if my widgets work or not. I'm not making artificial heart valves or selling to customers. Once I'm convinced I have something worth making (sorry I have to be so vague), and have a business plan that leads me to believe it can be done profitably, at that stage I'm going to be begging you to share your experience with me, and helping me identify the right machines, because it will matter at that point. Right now I'm just doing the best I can with what's available within the crazy parameters we've been discussing and hoping it works better than everyone is predicting. It's no big risk, not big money, I'm being very safety conscious (we'll get into the electronics at some point) so no harm will come from this.
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Do I want mirror polish, micon level output? Of course! Can I live with machine marks and 0.1mm accuracy? Yeah, honestly, it will still work for what I picture myself doing short term.

A machine with 0.1mm accuracy is a factor of 20X less accurate than typical professional CNC machines these days, FYI.
 

Bakafish

Aluminum
Joined
Feb 21, 2022
A machine with 0.1mm accuracy is a factor of 20X less accurate than typical professional CNC machines these days, FYI.

I know that, 0.1mm isn't my target at all, I'm just trying to communicate that not hitting 5 microns or less of accuracy and repeatability isn't going to crush my soul. There's no point in me making claims on how accurate this machine will be, ideally it could be quite acceptable, but reality still must be dealt with.
 








 
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